package com.facebook.presto.jdbc.internal.jackson.databind.jsontype.impl;
import java.io.IOException;
import com.facebook.presto.jdbc.internal.jackson.annotation.JsonTypeInfo.As;
import com.facebook.presto.jdbc.internal.jackson.core.*;
import com.facebook.presto.jdbc.internal.jackson.core.util.JsonParserSequence;
import com.facebook.presto.jdbc.internal.jackson.databind.*;
import com.facebook.presto.jdbc.internal.jackson.databind.jsontype.TypeDeserializer;
import com.facebook.presto.jdbc.internal.jackson.databind.jsontype.TypeIdResolver;
import com.facebook.presto.jdbc.internal.jackson.databind.util.TokenBuffer;
/**
* Type deserializer used with {@link As#WRAPPER_OBJECT}
* inclusion mechanism. Simple since JSON structure used is always
* the same, regardless of structure used for actual value: wrapping
* is done using a single-element JSON Object where type id is the key,
* and actual object data as the value.
*
* @author tatu
*/
public class AsWrapperTypeDeserializer
extends TypeDeserializerBase
implements java.io.Serializable
{
private static final long serialVersionUID = 5345570420394408290L;
public AsWrapperTypeDeserializer(JavaType bt, TypeIdResolver idRes,
String typePropertyName, boolean typeIdVisible, Class<?> defaultImpl)
{
super(bt, idRes, typePropertyName, typeIdVisible, null);
}
protected AsWrapperTypeDeserializer(AsWrapperTypeDeserializer src, BeanProperty property) {
super(src, property);
}
@Override
public TypeDeserializer forProperty(BeanProperty prop)
{
if (prop == _property) { // usually if it's null
return this;
}
return new AsWrapperTypeDeserializer(this, prop);
}
@Override
public As getTypeInclusion() {
return As.WRAPPER_OBJECT;
}
/**
* Deserializing type id enclosed using WRAPPER_OBJECT style is straightforward
*/
@Override
public Object deserializeTypedFromObject(JsonParser jp, DeserializationContext ctxt)
throws IOException, JsonProcessingException
{
return _deserialize(jp, ctxt);
}
@Override
public Object deserializeTypedFromArray(JsonParser jp, DeserializationContext ctxt)
throws IOException, JsonProcessingException
{
return _deserialize(jp, ctxt);
}
@Override
public Object deserializeTypedFromScalar(JsonParser jp, DeserializationContext ctxt)
throws IOException, JsonProcessingException
{
return _deserialize(jp, ctxt);
}
@Override
public Object deserializeTypedFromAny(JsonParser jp, DeserializationContext ctxt)
throws IOException, JsonProcessingException
{
return _deserialize(jp, ctxt);
}
/*
/***************************************************************
/* Internal methods
/***************************************************************
*/
/**
* Method that handles type information wrapper, locates actual
* subtype deserializer to use, and calls it to do actual
* deserialization.
*/
private final Object _deserialize(JsonParser jp, DeserializationContext ctxt)
throws IOException, JsonProcessingException
{
// first, sanity checks
if (jp.getCurrentToken() != JsonToken.START_OBJECT) {
throw ctxt.wrongTokenException(jp, JsonToken.START_OBJECT,
"need JSON Object to contain As.WRAPPER_OBJECT type information for class "+baseTypeName());
}
// should always get field name, but just in case...
if (jp.nextToken() != JsonToken.FIELD_NAME) {
throw ctxt.wrongTokenException(jp, JsonToken.FIELD_NAME,
"need JSON String that contains type id (for subtype of "+baseTypeName()+")");
}
final String typeId = jp.getText();
JsonDeserializer<Object> deser = _findDeserializer(ctxt, typeId);
jp.nextToken();
// Minor complication: we may need to merge type id in?
if (_typeIdVisible && jp.getCurrentToken() == JsonToken.START_OBJECT) {
// but what if there's nowhere to add it in? Error? Or skip? For now, skip.
TokenBuffer tb = new TokenBuffer(null);
tb.writeStartObject(); // recreate START_OBJECT
tb.writeFieldName(_typePropertyName);
tb.writeString(typeId);
jp = JsonParserSequence.createFlattened(tb.asParser(jp), jp);
jp.nextToken();
}
Object value = deser.deserialize(jp, ctxt);
// And then need the closing END_OBJECT
if (jp.nextToken() != JsonToken.END_OBJECT) {
throw ctxt.wrongTokenException(jp, JsonToken.END_OBJECT,
"expected closing END_OBJECT after type information and deserialized value");
}
return value;
}
}